Hydraulic turbo-couplings



June 27, 1961 FIT-SINCLAIR HYDRAULIC TURBO COUPLINGS Y 5 Sheets-Sheet 1Filed March 51, 1954 ww-wrok' HaroZd ianciazfi 9 ATTORNEY June 27, 19615 H. SINCLAIR 2,989,851

HYDRAULIC TURBO-COUPLINGS .Filed March 31, 1954 5 Sheets-Sheet 2 //vVENTOR Harold dine/air June 27; 1961 v H. SINCLAIR 2,989,851

HYDRAULIC TURBO-COUPLINGS Filed March 31, 1954 I 3 Sheets-Sheet 3 Harold51ml) fi ,w adv- ATTORNEY United States Patent Ofiice Patented June 27,1951 This invention relates to hydraulic turbocouplings of the Fottingertype wherein means are provided for varying the filling of the workingcircuit during operation of the turbo coupling to vary the torquetransmitting capability thereof.

Turbo couplings of the type referred to are known in which an adjustablescoop tube feeds working fluid from a rotating reservoir to a workingcircuit, and the working chamber of the coupling is provided withleak-off nozzles which permit working fluid to flow at a restricted ratefrom the working circuit to the reservoir. In a coupling of this type,which may be termed a scoop control coupling it is known to make therotating reservoir about one third greater in diameter than the outerprofile diameter of the working chamber so that the reservoir is capa--ble of taking up all the fluid from the working circuit without overflowwhen the coupling is stationary, and also when the coupling is rotatingand the scoop tube is fully retracted. The working circuit of a scoopcontrol coupling can be filled relatively rapidly via the scoop tube,but the circuit can empty only relatively slowly due to the restrictionimposed by the leak-off nozzles on the flow of fluid from the circuit.This disadvantage can be overcome by the provision of quick-emptyingvalves, but this measure complicates the otherwise simple constructionof the coupling. It is a characteristic feature of such couplings thatthe rate of circulation through the working chamber and the leak-oilnozzles varies with the degree of filling of the Working circuit, andthe rate of flow decreases as the fll-ling of the working circuit isreduced.

Turbo couplings of the type referred to are also known in which theworking chamber is in free communication with the scoop tube chamber oris provided with relatively large openings which are situated near theperiphery of the chamber and permit an unrestricted flow of fluid out ofthe working chamber to the adjacent rotating scoop tube chamber which isabout the same diameter as the outer profile diameter of the workingcircuit, and. wherein an adjustable scoop tube is disposed which feedsfluid from the scoop tube chamber to a sump, a pump being provided whichreturns fluid from the sump to the working circuit. In such a coupling,which may be termed a scoop trimming coupling the emptying of theworking chamber may be rapid, provided that a scoop tube of suitablylarge bore is employed, but since filling is effected by the pump therate of filling is relatively low unless a pump of high capacity isemployed.

In a scoop triming coupling the scoop tube is retracted to increase thefilling (by allowing more fluid to accumulate in the coup-ling as awhole) and the scoop tube is inserted in order to reduce the filling (bytransferring more fluid to the sump). A scoop trimming coupling has theadvantage that the circulation of fluid can be at a constant rateirrespective of the degree of filling of the working chamber, since itis determined by the pump. On the other hand a separate tank and pumpare required for its operation, whereas a scoop control coupling is aselfcontained unit.

In a scoop control coupling the scoop tube is inserted into the fluid inthe reservoir chamber in order to increase the filling of the workingcircuit (by transferring more oil from the reservoir to theworkingcircuit) and is retracted in order to reduce the filling (by allowingmore fluid passing through the leak-off nozzles to accumulate in thereservoir chamber).

It will be seen therefore that each type of coupling has advantages anddisadvantages with respect to the other type, and that neither type inits simplest form has the capacity of both rapid filling and rapidemptying of the working circuit.

The invention arises from the requirement of providing a powertransmission system incorporating two turbo couplings which are adaptedfor being operated together and in such manner that the working circuitof one coupling is filled and the working circuit of the other couplingis empty; or conversely. Provision may be made for both' No. 1,768,938,or for providing power transmission from a prime mover to a drivenmember through two power paths of different speed ratios, or forproviding drive from a prime mover to two driven members, for example,fans, pumps or compressors.

In such systems, whichever of the previously described form of scooptrimming or scoop control coupling is employed, there will be thedisadvantage that changeover from the condition in which one coupling isoperative to the condition in which the other coupling is operative willnecessarily be slow, since either the coupling which is to becomeoperative will fill only slowly or the coupling which is to becomeinoperative will empty only slowly. If the couplings are sointerconnected that changeover is effected by an actual flow of fluidfrom one coupling to the other as in the simplest form of thearrangement described in patent specification No. 2,187,656, then therewill be relatively slow emptying and slow filling of both couplings. Theobject of the invention is to provide a turbo coupling which whenassociated with a second turbo coupling in a power transmission systemas above-mentioned, enables the changeover time to be reduced veryappreciably as compared with systems incorporating simple designs ofcouplings of known types, e.g. of the scoop control type or of the scooptrimming type previously described.

According to the invention there is provided a hydraulic turbo coup-lingprovided with a rotatable reservoir chamber which is in freecommunication with, and is radially beyond the outer profile diameterof, the working circuit of the turbo coup-ling, and a scoop tube whichleads to the exterior of the turbo coupling, and the scoop orifice ofwhich is insertible into and retractable from said reservoir chamber.

According to the invention in a further form a power transmission systemmay incorporate two turbo couplings at least one of which is inaccordance with the last we ceding paragraph, the scoop tube of eachcoupling being arranged to lead either directly or via suitable portsand passages to the working chamber of the other coupling.

The effective volumetric capacity of the aforesaid reservoir chamber maybe equal to or less than the full capacity of the working circuit.Alternatively the reservoir chamber may be of full volumetric capacitybut the travel of the scoop tube may be suitably limited to transferonly the required volume of fluid from the reservoir chamber.

The two scoop tubes of the two couplings may be independently operable,or they may be mechanically or otherwise interconnected for uni-control.In some constructions the two scoop tubes may be provided in effect by asingle double-ended scoop tube with a passage right through from end toend and the ends of which are both formed as scoop tube orifices whichare adapted to project into the respective reservoir chambers of the twoturbo couplings. For very rapid rates of transfer of liquid two or moredouble-ended scoop tubes of this type may conveniently be utilised.

In order that the invention may be clearly understood and readilycarried into effect it will now be described in more detail withreference to the accompanying diagrammatic drawings, in which:

FIGS. 1 to 3 illustrate two similar turbo couplings according to theinvention, with a scoop tube common to the two couplings,

FIG. 1A shows a practical form of the means that may be employed foractuating the scoop tube means in the embodiment of the inventiondiagrammatically illustrated in FIGS. 1 to 3, and

FIGS. 4 to 6 illustrate two similar turbo couplings according to theinvention provided with individual, mechanically inter-connected scooptubes.

FIGURES l to 3 show an arrangement comprising two turbo couplings A andB. The turbo coupling A comprises an impeller 1 fixed on a sleeve 2, androtatable with a casing 3 fixed on an input shaft 4. The casing 3encloses the runner 5, which is fixed On an output shaft 6 on which thesleeve 2 is rotatably mounted. The turbo coupling A has a reservoir 7which is rotatable with the impeller 1 and input shaft 4, and which ascan be seen projects radially well beyond the outer profile diameter ofthe working chamber of the turbo coupling A. The reservoir 7 comprisesan annular end wall 7a joined to the casing 3, a cylindrical outer wall7b, and a frustoconical wall 70 which projects towards and into nearcontact with a stationary housing 8 in which the scoop tube is slidablymounted. Large openings 9 in the back of the impeller 1 place theworking chamber of turbo coupling A in unrestricted communication withreservoir 7.

In the drawing the same reference numerals have been employed (withindices) for those parts of turbo coupling B which correspond to partsof coupling A. Coupling B is similar to coupling A except that therunner is fixed on an output sleeve shaft 10 rotatable relative tooutput shaft 6.

The turbo coupling A is provided with a scoop tube 11, and the turbocoupling B is provided with a scoop tube 11', the scoop tubes 11 and 11having oppositely directed scooping orifices, and being capable of beinginserted into and withdrawn from the reservoirs 7 and 7' respectively.The scoop tube 11 leads from the reservoir 7 to the exterior of theturbo coupling A, and the scoop tube 11' leads from reservoir 7 to theexterior of turbo coupling B, and the two scoop tubes are mechanicallyinterconnected so that as either one of them is withdrawn from itsassociated reservoir the other is automatically inserted into itsassociated reservoir. In the arrangement shown in FIGS. 1 to 3 thismechanical interconnection is effected in a simple manner by forming thetwo scoop tubes as parts of a single, double-ended scoop tube which ismounted so as to be slidable longitudinally in the support 8. The scooptube 11 thus leads from reservoir 7 of coupling A directly to thereservoir 7 of coupling B, via the scoop tube 11, and the scoop tube 11leads directly from the reservoir 7' of coupling B to the reservoir 7 ofcoupling A, via the scoop tube 11. Means are provided for displacing thescoop tubes longitudinally in the support 8. The said means may comprisea rack provided on the scoop tubes and a pinion co-operating with therack and provided with an operating lever.

The two turbo couplings A and B are mounted within a casing 12 the lowerportion of which serves as a sump, the shaft 4 and shaft 10 beingjournalled in bearings in the end walls of the casing 12.

The working chambers of the two turbo couplings have substantially thesame volume, and the reservoirs 7 and 7' each have the same volume asthe respective working chambers.

The arrangement shown in FIGS 1 to 3 is suitable for use with a constantspeed driving means which may comprise for example an A.C. inductionmotor or a diesel engine coupled to the input shaft 4. It will beassumed that the output sleeve shaft 10 is drivably connected to adriven member via a forward gear train, and that the output shaft 6 isdrivably connected to the same driven member via a reverse gear train.

The total quantity of working fluid (oil) in the rotating parts of thetwo couplings is rather more than the volume of one working chamber withits associated scoop tube chamber and reservoir chamber, the scoop tubechamber being regarded as that part of the reservoir chamber that isradially within the outer periphery of the working circuit.

FIG. 1 shows the neutral condition of the couplings, the scoop tubes 11,11' being in a mid-position. In this mid-position the scooping orificesof the scoop tubes are approximately at the levels of the outer profilediameters of their associated working chambers, and both workingchambers are empty, the reservoir chambers 7 and 7 being full. In thiscondition no power is transmitted from the input shaft 4 either to theoutput sleeve shaft 10 or to the output shaft 6.

When it is required to drive the driven member in forward direction, thescoop tubes 11 and 11 are moved longitudinally to the positions shown inFIG. 2, wherein the scoop tube 11 is fully inserted into the reservoir7, and the scoop tube 11 is fully retracted from the reservoir 7. Oil israpidly transferred from reservoir 7 of turbo coupling A, via the scooptubes 11 and 11', to the reservoir 7' of turbo coupling B, and due tothe free communication between the reservoir chamber 7' and the workingchamber of coupling B, the working circuit of the latter is rapidlyfilled. Since the scooping orifice of scoop tube 11 is now atapproximately the level of the inner profile diameter of turbo couplingB, no oil is transferred from reservoir 7' to reservoir 7. Consequently,reservoir 7 and the Working chamber of coupling B are full, butreservoir 7 and the working chamber of coupling A are empty. Under theseconditions, power is transmitted from the input shaft 4 to the outputshaft 10 via turbo coupling B, to drive the driven member in forwarddirection. No power is transmitted by the empty turbo coupling A.

In order to change to reverse drive, the scoop tubes are adjusted to thepositions shown in FIG. 3, in which scoop tube 11 is fully inserted intothe reservoir 7' of coupling B and the scoop tube 11 is fully withdrawnfrom the reservoir 7 of coupling A. Oil is rapidly transferred fromreservoir 7' to reservoir 7, via the scoop tubes 11' and 11, until thereservoir 7 and the working chamber of coupling B are empty and thereservoir 7 and the working chamber of coupling A are full. Under theseconditions power is transmitted from the input shaft 4 to the outputshaft 6 via the turbo coupling A, and the driven member is driven inreverse. No power is transmitted via the turbo coupling B.

The changeover from forward to reverse drive can be effected veryquickly owing to the direct flow of oil from the working circuit of onecoupling to the working circuit of the other coupling.

The sump provided by the stationary casing 12 serves to receive anyleakage oil from the turbo couplings, and a small pump 30 is providedfor returning the leakage oil from the sump into the rotatingreservoirs. This pump, which may be of small capacity, is convenientlydriven from the input shaft 4. It also serves to return to the couplingsoil that has drained into the sump when the couplings have beenstationary. The inlet pipe 41 of the pump 30 communicates with theinterior of the sump 12, and the outlet pipe 42 of the pump communicates(see FIG. 1A) with a duct 43 in the housing 8, which duct communicatesvia a port 44 with the working circuits of the couplings.

As shown in FIG. 1A, the scoop tube means 11, 11 is slidably mounted inthe stationary housing 8, and is provided with rack teeth 35. A controlrod 36, also slidable in the housing 8, is provided with rack teeth 37,and a pinion 39 has its teeth in mesh with the rack teeth 35 and 37.Longitudinal movement of the control rod 36 (which movement may beeffected by hand or by means of a servo motor coupled to the link 40)causes rotation of the pinion 39 and thus sliding movement of the scooptube means 11, 11'.

In the arrangement shown in FIGS. 4 to 6 two turbo couplings are againprovided, their general arrangement being similar to that of FIGS. 1 to3, but the couplings have individual scoop tubes which areinterconnected by a mechanical linkage.

The impeller 1 of turbo coupling A is fixed on the input shaft 4, andthe runner 5 of coupling A is fixed on the output shaft 6. The runner 5'of turbo coupling B is fixed on sleeve shaft 10, and the impeller 1' isjournalled on sleeve shaft 10. An annular partition 14 is joined at itsperiphery to a casing 15 the end walls of which project inwardly towardsstationary supoprts 16 and 16'. An inner casing 17 is connected to thepartition 14 and to the impeller 1 which is mounted on input shaft 4,and an inner casing 17' is connected to the partition 14 and, adjacentthe shaft 10, to the impeller 1', reservoir chambers 18 and 18 thusbeing formed. The inner casings 17 17' have large ports 19 and 19'respectively which atford free communication between the reservoirs 18and 18' and the working chambers 20, 20' respectively of the associatedturbo couplings A and B.

The scoop tube 21 of turbo coupling A is slidable longitudinally in thesupport 16, and is provided with a port which communicates with anannular duct 22 in the support 16. At this upper end the scoop tube isprovided with a rod 23 connected to one arm of a bell crank lever 24pivotally mounted on a stationary outer casing 25 which serves as asump. The arrangement of the scoop tube 21' of turbo coupling B issimilar to that of the scoop tube 21 of turbo coupling A, the rod 23 ofscoop tube 21 being connected to one arm of a bell crank lever 24'mounted on the outer casing 25. The bell crank levers 24 and 24' areinterconnected by a link 26.

The annular ducts 22 and 22' in the supports 16 and 16' areinterconnected by a duct 27, to the centre of which is connected abranch pipe 28 which leads via a valve 29 to the sump formed by theouter casing 25. A small pump 30, which may be driven from the inputshaft 4, serves to transfer oil from the sump to the annular duct 22,and thence to the working chambers and reservoir chambers of the twoturbo couplings.

The working chambers are of equal capacity. The capacities of thereservoir chambers 18 and 18', which are radially beyond the outerprofile diameter of the working circuits, are equal to one another, butare each equal to about 60% of the volume of either of the workingcircuits 20 and 20.

The arrangement of FIGS. 4 to 6 is suitable for driving from a dieselengine through forward and reverse gears via couplings B and Arespectively.

FIG. 4 shows the neutral condition, in which the link 26 is adjusted sothat the two scoop tubes 21 and 21' are within the respective scoop tubechambers and are not inserted into the reservoirs 18 and 18. In thisneutral condition, the scooping orifices are slightly'radially withinthe outer profile diameter of the couplings, and the oil filling is suchthat in this condition each reservoir 18 and 18' is full, and eachworking circuit contains oil to 20% of its full capacity. The valve 29is open to return to the sump the oil delivered by the pump 30.

Assuming that the engine is idling, the slight drag torque due to the20% filling of each working circuit is of no consequence, and no torquewill be transmitted to the driven member since the runner 1 is connectedto it via the reverse train and the runner 1 is connected to it via theahead train.

When it is required to drive the driven member in forward direction, thelink 26 is moved to the left. This has the effect (FIG. 5) of fullyinserting scoop tube 21 into the reservoir 18, and of withdrawing thescoop tube 21. The 60% volume of oil in reservoir 18 is therebytransferred, together with the 20% volume in working circuit 20 ofcoupling A, to the right hand coupling B, via scoop tube 21, annularduct 22, pipe 27, annular duct 22, and a port 32'. Since the reservoir18 of coupling B was already full and the working circuit 20 already hada 20% filling, the result of the transfer of oil from coupling A tocoupling B is that the working circuit of coupling B rapidly becomesfull.

Power is thereby transmitted from the input shaft 4 to the driven membervia turbo coupling B, shaft 10 and the forward gear train. No power istransmitted by the now empty turbo coupling A. I

To change from forward to reverse drive, the link 2 is moved to theright so that, as shown in FIG. 6 the scoop tube 21 is fully insertedinto the reservoir 18' and the scoop tube 21 withdrawn from thereservoir 18. All of the oil in the turbo coupling B is therebytransferred to turbo coupling A, via scoop tube 21, annular duct 22'duct 27, annular duct 22 and a port 32. Since the working circuit ofturbo coupling A is now full and the working circuit of turbo coupling Bis empty, power is transmitted from input shaft 4 to the driven membervia turbo coupling A, output shaft 6, and the reverse gear train. Nopower is transmitted by the empty coupling B.

When the system is set for forward or reverse drive, (FIGS. 5 and 6) thevalve 29 is closed, as shown, for example by means mechanicallyconnecting the valve to link 26. The excess of oil delivered by the pump30 into the rotating reservoirs 18 and 18' overflows from the centre ofthe full coupling and returns to the sump.

I claim:

1. A power transmission system comprising an input shaft, two outputshafts, a sump, two hydraulic turbo couplings each comprising a vanedimpeller and a vaned runner defining a toroidal working circuit, theimpellers of said couplings being drivably connected to said input shaftand the runners being drivably connected one to each of said outputshafts, a pump for feeding working liquid from said sump to said turbocouplings, scoop tube means adjustable from a position to transferworking liquid from one coupling to the other coupling to a secondposition in which flow of working liquid between said couplings isminimized, a rotatable reservoir chamber in each coupling in freecommunication with the working circuit of the said coupling, each saidreservoir chamber having a portion positioned radially beyond the outerprofile diameter of the working circuit of the said coupling and thesaid portions of said reservoir chamber of both couplings having acombined capacity such that the working circuits of both couplings canbe selectively filled and emptied depending on the setting of said scooptube means in said reservoir chambers to effect flow of working liquidfrom one of said couplings to the other coupling and both workingcircuits can be substantially emptied to the said portions of saidreservoir chambers when said adjustable scoop tube means are moved tosaid second position.

2. A power transmission system comprising an input shaft, two outputshafts, a sump, two hydraulic turbo couplings each comprising a vanedimpeller and a vaned runner defining a toroidal working circuit, theimpellers of said couplings being drivably connected to said input shaftand the runners being drivably connected one to each of said outputshafts, a pump for feeding working liquid from said sump to said turbocouplings, each coupling being provided with a rotatable reservoir chamher in free communication with the working circuit and a portion ofwhich reservoir chamber is positioned radially beyond the outer profilediameter of the said working cir- 1 cuit, at least one scoop tube withscoop orifices at both ends, said scoop tube being adjustable to andbetween two end positions, such that the movement of the scoop tube toone of said end positions serves to transfer working liquid from onecoupling to the other coupling, and the movement of the scoop tube tothe other of said end positions serves to transfer liquid from saidother coupling to said one coupling, the said portions of said reservoirchambers radially beyond the outer profile diameters of said workingcircuits having a combined capacity such that with said scoop tube setto a predetermined position intermediate said end positions the workingcircuits of both couplings are substantially emptied to the saidportions of said reservoir chambers.

3. A power transmission system comprising an input shaft, two outputshafts, a sump, two hydraulic turbo couplings each comprising a vanedimpeller and a vaned runner defining a toroidal Working circuit, theimpellers of said couplings being drivably connected to said input shaftand the runners being drivably connected one to each of said outputshafts, a pump for feeding working liquid from said sump to said turbocouplings, each coupling being provided with a rotatable reservoirchamber in free communication with the working circuit and has a portionpositioned radially beyond the outer profile diameter of the saidworking circuit, at least one scoop tube with scoop orifices at bothends, said scoop tube being adjustable to a plurality of positionscomprising two end and a mid-position such that movement of the scooptube away from said mid-position in one direction serves to transferliquid from one coupling to the other coupling, and from saidmid-position in the other direction serves to transfer liquid from thesaid other coupling to the said one coupling, the portions of saidreservoir chambers radially beyond the outer profile diameters of theirworking circuits having a combined capacity such that with said scooptube in said mid-position the working circuits of both couplings aresubstantially emptied to said portions of said reservoir chambers.

4. A power transmission system comprising a sump, two hydraulic turbocouplings each comprising a vaned impeller and a vaned runner defining atoroidal working circuit, each coupling having a rotatable reservoir,chamber in free communication with the working circuit of the saidcoupling and having a portion positioned radially beyond the outerprofile diameter of the working circuit of said coupling, a pump forfeeding working liquid from said sump to said turbo couplings, anadjustable scoop tube in each coupling in communication with the workingcircuit of the other coupling and adjustable from a position to transferworking liquid from one coupling to the other coupling to a secondposition in which flow of working liquid between said couplings isminimized, said portions of said reservoir chambers having a combinedcapacity such that said working circuits can be selectively filled andemptied depending upon the setting of the adjustable scoop tubes toeffect flow of working liquid from one of said couplings to the other ofsaid couplings and both working circuits can be substantially emptied tothe said portions of said reservoir chambers when said adjustable scooptubes are moved to said second position.

5. A power transmission system comprising a sump, two hydraulic turbocouplings each comprising a vaned impeller and a vaned runner defining atoroidal working circuit (each coupling being provided with a rotatablereservoir chamber in free communication with the working circuit andhaving a portion positioned radially beyond the outer profile diameterof the said working circuit, a pump for feeding working liquid from saidsump to said turbo couplings, at least one scoop tube with scooporifices at both ends, said scoop tube being adjustable to any of aplurality of positions including two end positions, such that theadjustment of the scoop tube to one of said end positions serves totransfer working liquid from one coupling to the other coupling and theadjustment of the scoop tube to the other of said end positions servesto transfer liquid from said other coupling to said one coupling, theportions of said reservoir chambers that are radially beyond the outerprofile diameters of their working circuits having a combined capacitysuch that in a neutral setting of said scoop tube in which flow ofliquid between the couplings is minimized the working circuits of bothcouplings are substantially emptied to the said portions of saidreservoir chambers.

6. A power transmission system comprising a sump, two hydraulic turbocouplings each comprising a vaned impeller and a vaned runner defining atoroidal working circuit, each coupling being provided with a rotatablereservoir chamber in free communication with its working circuit andhaving a portion positioned radially beyond the outer profile diameterof the said working circuit, a pump for feeding working liquid from saidsump to said turbo couplings, a scoop tube with scoop orifices at bothends, said scoop tube being adjustable to a plurality of positionsincluding a mid-position such that movement of the scoop tube away fromsaid mid-position in one direction serves to transfer liquid from onecoupling to the other coupling, the movement of the scoop tube away fromsaid mid-position in the other direction serves to transfer liquid fromthe said other coupling to the said one coupling, the portions of saidreservoir chambers positioned radially beyond the outer profilediameters of their working circuits having a combined capacity such thatwith said scoop tube in said mid-position the working circuits of bothcouplings are substantially emptied to the said portions of saidreservoir chambers.

References Cited in the file of this patent UNITED STATES PATENTS1,987,985 Bauer et al. Ian. 15, 1935 2,202,243 Alison May 28, 19402,491,483 Dolza et a1. Dec. 20, 1949 2,492,456 Becker Dec. 27, 1949FOREIGN PATENTS 1,043,365 France June 10, 1953 815,133 Germany Sept. 27,1951

